Hi everyone. I'm new here, I've come across Briskoda before and have signed up now for some help. I posted the following on PistonHeads yesterday and it was suggested I post it here as well, so here goes:

 

My first car is a 2007 Seat Ibiza 1.4, I've had it since July and I love it. However:

 

It has two faults with the passenger door. The first of which is the door switch doesn't work, meaning the interior light doesn't come on when the passenger door is open and if I unlock the car and get in the passenger side, I get locked in after 30 seconds because the car doesn't know the door has been opened.

 

The second fault is with the locking itself. When locked with the button on the key, so all the door handles are locked, it works fine. When locked with the button inside the driver's door, so only the exterior handles are locked, the passenger door doesn't lock at all.

 

I took it to a local garage the other day and they dismantled the passenger door and suggested the locking mechanism was at fault. I can't afford to spend £130 on a new one so I ordered a brand new but non-genuine part from Ebay, £40. My Haynes manual states that the door switch is built into the locking mechanism, so replacing it should have fixed both problems. I installed the new part today and the door switch now works perfectly: interior light and central locking both know when the door is open. The problem is that the locking still doesn't work properly, with almost exactly the same symptoms as before: not locking when locked from the inside. I have no reason to believe the new mechanism is faulty, so where does that leave me?

 

All I can think to do is buy a diagnostic fault reader and see if comes up with any codes. Is this worth doing? Any other help gratefully received!

It makes me wonder if the issue is connector(s) in the door loom rather than a gubbins.

It's a possibility I suppose but I had to unplug every connector in the door to get the window regulator mechanism thing out the way to get to the lock and I didn't notice anything wrong. I should probably also mention that both faults were intermittent, I don't know if the door switch is still working this morning, I'll have a look in a minute.

 

Could it be a dodgy earth connection somewhere?

Now guess where the door earths are; yes, in the door looms.

Ah. I see. Forgive me, I have limited experience with car mechanics and electrics. I'll have a look at the wiring diagrams and see what I can find. Would a fault code reader be of any use?

 

Edit: According to the wiring diagram the passenger door lock has three wires leading to the "convenience system control unit" under the dashboard, one to the "on-board power supply control unit" and one to the earth point in front of the gear stick. I'm guessing the fault isn't with the power supply unit as the lock doesn't appear to suffer from a lack of power. I'll take the centre console out and see if I can find the earth point. I really hope it isn't the convenience system ECU!

Edited 30 October, 201411 yr by LDB

I dismantled the door again this morning and checked the earth wire from the lock mechanism through to the earth point, all is well. That points towards an ECU fault, however I now think the new mechanism is faulty as I closed the door, locked the car, unlocked the car and found that the passenger door won't unlock. AARRRGGHHHH!

 

I've just realised there's a lever in the mechanism that has to be hooked up to a spring before the mechanism is refitted to the door. Guess which muppet didn't hook up the spring before putting it back together this morning!

 

So now I have to find a way of breaking into my own car!

Edited 31 October, 201411 yr by LDB